JP2021536329A - Wearable active auxiliary device - Google Patents

Abstract

INDUSTRIAL APPLICABILITY The present invention relates to a wearable active assist device comprising an actuator and a control device, wherein the actuator provides limb assistance during use and is actively assisted via at least one force transmission element stretched and contracted by the actuator. Combined, the controller outputs a signal processing stage for processing inputs from multiple sensors and input signals from multiple sensors, and a motor activation signal according to the processed sensor signals. With an output stage, the controller further has a limb assist degree selection input for selecting the limb assist degree, and the signal processing stage corresponds to the movement or posture currently detected by multiple sensors. The extension of at least one force transmitting element to be stretched is continuously modeled, and the actuator is continuously actuated according to the modeled extension of at least one force transmitting element and in response to the selected minimum limb assistance degree. Adapted to output a signal. [Selection diagram] Fig. 1

Description

The present invention relates to a wearable active auxiliary device.

Wearable active auxiliary devices are well known. They can be used to assist an injured patient in his or her exercise, especially due to an accident, due to recent surgery, or due to another medical condition. Wearable active auxiliary devices can also be used to help the patient exercise at least in a near-normal manner and to train the user to exercise in a normal manner without the auxiliary device. This can be done not only by actively assisting limb movements, but also by providing external support and stability.

The assistance provided by the device may not require the full power possible for a given active auxiliary device when the patient recovers or, in the case of progressive disease, before the deterioration of the patient's health. .. In many cases, a particular limb does not need to be assisted at all or fully assisted. In particular, it may be helpful to phase out assistance or reduce overall assistance to zero, for example during a training session for a patient recovering from an accident. However, this is difficult with standard wearable active auxiliary devices.

Documents "Smart Suit for Horse Trainers-Power and Skill Assist Based on Semiconductor on Semi-active Assist and Energy Control", International Convention, Tennary, Canada, International, Canada, 10 Kusaka et al. , Inject action number 11 769922 proposes a power assisting system in which the force generated by an elastic material is controlled by adjusting the tension or offset of the elastic material. It has been proposed to synchronize the user's exercise with assistive force, and for that purpose, it has been proposed to apply a periodic input control method, in such an input control method, the periodic exercise is It changes with horse-like exercise, and the length of the elastic material is adjusted to synchronize with the duration of horse-like exercise to obtain appropriate assistance.

US 2018/0078391 describes walking assistance based on estimated joint torque that requires the user's myoelectric potential (EMG) and motion data as inputs. Based on different estimated joint torques, device parameters are set for locomotion, which mimics joint torques produced by the human body in particular. Devices known from DE 10 2012 219 429 A1 are controlled by measuring the residual energy of the actuator and used in conjunction with the residual detector to determine the degree of assistance.

From WO2018 / 122106, a softwareable muscle assist device is known, in which the tendon is shortened or lengthened relative to length and position using a DC motor to which a control signal is provided. Or be maintained. The controller may use arrays, or sensors for multiple motions and forces, and these arrays or sensors may be used in embodiments that estimate the user's posture and / or motion intent or current motion. Based on this information, the controller of the device may determine how to optimally support the user's movement, for example by varying the applied force and joint stiffness. The sensor equipment includes an inertial measuring unit on the shin and thigh of the leg for measuring the momentum of the leg, an inertial measuring unit for the arm for measuring the momentum of the arm, and an inertial measuring unit for measuring the movement of the torso. It has been proposed that it may include an inertial measuring unit of the body's center of gravity. It has also been proposed that load cells be placed in each tendon to measure force. It has been proposed that an encoder in the motor continuously measures the rotational position of the motor shaft of the actuator, thereby estimating the length of the tendon. It is stated that only the load cell and encoder combination and / or the encoder signal allows reliable control of the hardness and / or force level in the system. It is also stated that the motor applies a force equal to the effect of gravity and changes the hardness of the joint.

Wearable active devices known from WO / 2016/089466, WO / 2015/157731 and WO / 2018/039354 rely on cables to provide assistive power and may also provide minimal assistance. It also cannot follow the wearer's movements exactly. When no force is required, these devices switch to a mode in which there is sufficient slack in the force transfer cable to allow the user to perform the full range of motion without restraint. Therefore, these systems must first overcome excessive slack and cannot transmit force immediately when unexpectedly needed. Not only does this significantly reduce the bandwidth of these systems, but it also does not allow for a smooth start of force transfer. In addition, this principle is also energy inefficient as it requires the actuator to actively deliver additional cable to generate sufficient slack.

Some of the known wearable active assistive devices, in particular the softwareable muscle assistive devices known from WO2018 / 122106A1, provide very good assist to the user, while the desired degree of assist is at least for some time. It may be desired to be able to select the degree to which the limb is assisted or the plurality of limbs are assisted, even if it is 0 or negligible to the user. Providing the support that is actually needed more accurately can also be praised by many users.

U.S. Patent Application Publication No. 2018/0078391 International Publication No. 2018/122106

Smart Suit for Horse Trainers-Power and Skill Assist Based on Semi-active Assist and Energy Control ”, International Convention 20 Kusaka et al. , Inject access number number 11 769922

An object of the present invention is to provide a novel one for industrial use.

This object is achieved by the subject matter of the independent claims. Some of the preferred embodiments are claimed in the dependent claims.

According to the first basic idea of the present invention, it is a wearable active auxiliary device including a motor and a control device, in which the motor can be operated to provide limb assistance during use and can be expanded and contracted by the motor. Coupled to the limbs to be actively assisted via at least one force transfer element, the controller is for processing inputs for signals from multiple sensors and input signals from multiple signals. A wearable active auxiliary device having a signal processing stage and an output stage for outputting a motor activation signal according to the processed sensor signal further provides a limb assist degree selection input for the controller to select the limb assist degree. Having and the signal processor stage models the elongation of at least one force transfer element that can be expanded and contracted in response to the motion currently detected by multiple sensors, and the current state of at least one force transfer element that can be expanded and contracted. It is proposed that it be adapted to output a motor actuation signal according to the modeled extension of and in response to the selected minimum limb assist.

That is, the wearable active auxiliary device is reduced to zero by activating a motor that assists the normal limb in such a manner that the extension of the force transfer element is reliably controlled according to a model derived based on multiple sensor signals. It is proposed to have a selectable minimum degree of assistance that can be close limb assistance. This makes it possible to select the minimum aid from the tendon without disconnecting the actuators, motors and the like. In particular, the minimum limb assist level can be selected by a physical therapist, physiotherapist, doctor, etc., not even by the user himself, who wears the wearable active assist device, without even being noticed by the patient. The user who hears the motor has the impression that it is supported, as the motor continues to expand and contract at least one force transfer element even if no de facto support is provided.

Therefore, the placebo effect of a wearable active assistive device can be easily tested, especially if the patient needs to regain confidence in his (or her) own muscles. In addition, if it turns out that assistance must still be provided for a particular exercise, despite the expectations of a physiotherapist or similar, by modeling elongation and at least one force transmission element. By stretching and contracting, assistance can and is made available immediately. For the purposes of the present invention, the limb assist degree selection input is adapted so that at least two different degrees of support can be selected by switching the unit on, and the minimum limb aid degree is this minimum. It should be noted that the degree corresponds to one of these selectable degrees, even if it corresponds to a zero auxiliary.

It is noted that different degrees of assistance may be selected for both sides of the human body in a preferred embodiment, eg, assistance to the left leg is different from assistance to the right leg. If separate actuators are used to assist the limbs on the same side of the body, it is possible and advantageous to select different degrees of assistance for each limb. The output of the motor actuation signal can be modeled, for example, by simply referring to a particular signal indicating the current posture of the assisted limb in flexion or flexion, where the force transfer element is one of the assisted limbs. Since it extends across more than one joint to the motor, for example simultaneous assistance by one electric motor should be provided to the neck, thighs and hips by properly guided force transfer elements. It is possible to determine, for example, whether the thigh is vertical, horizontal, or in an intermediate position, depending only on the angle of the joint, the sensor signal that measures the orientation of each element, and so on. It is noted that it is possible. It is not necessary to determine if a person currently requesting minimal, preferably zero, assistance for a particular limb is moving according to a particular pattern, such as walking or climbing stairs.

Therefore, it is not necessary and not considered particularly advantageous to predict the next exercise to provide minimal limb assistance. The expansion and contraction of the force transmission element by the motor operated by the motor actuation signal controlled as proposed by the present invention does not have to depend on a predefined position trajectory, but one or more processed sensor signals. According to, and preferably, minimal limb assistance can be continuously provided regardless of the exercise or posture performed.

Nevertheless, it is possible to have at least one force transfer element stretch that closely matches the user's current behavior without predicting how the user will move next. It is very advantageous to rely only on the signals currently perceived by multiple sensors, not on the predicted motion pattern.

Nevertheless, it should be noted that the current exercise can still be identified along with the user's current exercise phase, even while using the wearable active assist device in transmission mode, which provides minimal limb assistance. be. In this way, the user's blood pressure or heart rate increases above a lethal level that can often result, for example, that the user has the impression that he / she is unable to cope with the current situation or that the actual effort is too great for the user. Therefore, it is possible to immediately assist a user who suddenly requests assistance without delay and without adverse effects.

Also, the accelerometer and / or the angular velocity sensor may indicate that the user begins to move in a fall mode and that the fall must be prevented. In such cases, it may be helpful to detect the current movement pattern, even if the actual expansion and contraction of the force-transmitting element while the system is in the minimal limb assist state is independent of such patterns. Sensor signals are conditioned and digitized so that the controller can be mounted using a hardware stage such as a hardware mounting filter or the like, or, as an alternative, the controller can be mounted as a software stage. It is noted to get. It includes a controller as an additional (software) module within an existing active auxiliary device, and in particular such a device is capable of immediately providing the appropriate sensor signal.

In a preferred embodiment, the plurality of sensors comprises a gyro sensor and / or an accelerometer and / or a magnetic sensor and / or a stretch sensor and / or a motion sensor and / or an angle sensor. (Multi-axis, especially triaxial accelerometers, gyro sensors and magnetic sensors are particularly useful in determining the current orientation of limbs and limb segments, and multiple on both proximal and distal sides of the joint. Providing a gyro sensor and / or an accelerometer makes it possible to determine the angle of a joint, or at least estimate it. The same can determine the direction of the Earth's magnetic field. Applies to magnetic sensors as described above, as well as related signal processing circuits such as buffers, amplifiers, A / D converters and the like, by varying ambient conditions such as temperature in a predictable manner. It should be noted that it can be affected. Therefore, in certain embodiments, having an additional ambient sensor, such as a temperature sensor, a pressure sensor, etc., and responding to signals derived from the additional ambient sensor. It may be preferred to compensate for potential variations in gyro sensors and / or accelerometers and / or magnetic sensors and / or extensibility sensors, as well as associated circuits.

It is noted that other sensors, such as a dedicated angle sensor for determining the angle of the joint, may be used. Motion sensors and / or angle sensors not explicitly listed are available, but stretchable sensors and / or future sensors such as new sensors and / or other known sensors are available. Can be foreseen. However, if a force sensor (eg, a strain gauge and the like) is not required to measure the tension in the force transfer element, this is particularly advantageous as it simplifies the arrangement and reduces costs. It should be noted that the reaction of the wearable active auxiliary device according to the present invention can be very fast even if the strain gauge is not attached to the force transfer element.

In a preferred embodiment, the active assistive device is adapted to assist the activity of one or more limbs, in particular at least one leg of the human body. It is possible to rely on control signals from only one leg to provide control signals. However, it may be preferred to use signals from both legs. For example, if the user begins to fall, high accelerations are expected and, in general, these cannot be assigned to any known typical behavior or motion. Therefore, relying on signals from both sides allows the system to determine faster that the zero or minimum auxiliary phase needs to be terminated immediately.

In a preferred embodiment, as shown above, the controller is independent of any force or tension display signal indicating a force and / or tension measurement in the force transfer element, especially the load cell sensor measurement signal. Independent of, adapted to model the elongation of the force transfer element. It is understood that if such force or tension is measured in any way, the corresponding signal can also be used in transmission mode. However, in most applications, if neither such force or tension indication signal is actually required and no such corresponding sensor signal is required, they are not required. It can be considered an advantage as it can only function to implement a transparent mode. Therefore, it is also understood that while such force or tension sensors can be used in transmission mode, they are not needed if they are not considered important for implementing additional functionality. To.

In a more preferred embodiment, the force transfer element itself is largely non-extensible. That is, the force that the user can exert on the force transmitting element during normal use is not suitable for allowing large extension of the force transmitting element.

Here, as shown above, the wearable active auxiliary device according to the invention relies on a module for assessing the currently required elongation of the force transfer element by actuating the motor. In this context, it should be noted that if the cable corresponds to a force transfer element, the elimination of the cable's twist and the start of the twist are considered to stretch the force transfer element.

If physical parameters such as size, limb length, perimeter of the leg and the like are known, it is understood that the basic modeling of elongation is almost precise.

However, it is very time consuming for the user to be measured very precisely, especially for physiotherapists and the like, which increases the overall cost of using the wearable active auxiliary device according to the present invention. There is often a need or at least such a desire that it does not need to be precisely measured.

Therefore, it is highly preferred to allow wearable active auxiliary devices to be used without generally accurately determining dedicated physical parameters for each single user. Therefore, in a more preferred embodiment, the restorative element is provided in series with the stretchable force transfer element between the limb and the motor. The use of such restorative elements (eg, coil springs) allows small errors in the currently required expansion and contraction determination of the force transfer element to remain undetected by the user.

In a preferred embodiment, a restrictor is provided that limits or constrains the elongation of the restorative element (eg, constrains the elongation of the spring to maximum possible elongation), allowing further elongation of the restorative element. It is even more preferred to deprive the spring or other restorative element of any additional force applied without it. For example, a cord or wire of a particular length is provided within the coil spring. The cord can be attached at the same point as the end of the spring, whereby the restrictor can also be placed between the limb and the motor used to assist the limb when actuated. If the rope is longer than the spring coil unless the spring coil is stretched, then any force applied to the force transfer element (eg, the force due to the discrepancy between the model and the user) will lead the spring stretch to a certain degree. ..

The force is not deprived by the restrictor while the spring extension remains low. However, when the spring is stretched to the maximum possible, any additional force is deprived by the restrictor, thereby not allowing further stretching of the restorative spring. That is, the restrictor constrains the elongation to a certain maximum possible, especially if actual support or assistance is provided. By properly selecting the appropriate maximum possible elongation of the stability spring element and the appropriate resilience factor, any deviation between the model and the extension actually required for a particular user can be determined. Care may be taken not to affect the intended behavior of the wearable active auxiliary device during actual assistance or to make the device sensible during transmission mode.

In a preferred embodiment, the stability factor is between the standardized model and the correct stretch for a given user because of the maximum residual force allowed at the selected minimum limb assist. It has a stability factor that is extended by less than or equal to the maximum possible deviation of. In this context, it is not necessary to make very precise measurements of the user, but it is clear that it is possible and preferable to provide multiple resilience elements that differ in both resiliency and maximum possible length. In typical situations, the maximum possible deviation can be a few centimeters (eg 3-7 cm). This distance can be easily overcome even in the case of urgent changes in limb assistance given at standardized motor speeds. These preferred maximum possible lengths, in turn, allow residual forces due to the elongation of the restorative element in the event of a discrepancy with a model that is almost undetectable by the user, leaving the discrepancy almost or full time undetectable. Make sure that.

As shown above, it is possible to determine the phase in the identified current motion and output the motor actuation signal in response to the modeled elongation. Although it may be possible to predict the actual stretch, however, the transmission mode provided by the wearable active auxiliary device according to the invention does not require knowledge of the walking phase, for example, as the actuation profile is not predefined. It should be noted that the system does not depend on the exact walking cycle. In particular, instead of relying on a particular walking phase, other parameters such as continuous force adjustment depending on knee angle and the like may be used.

However, the controller can nevertheless be adapted to identify specific activities such as walking, standing, walking up or downhill, climbing stairs, shifting to a sitting position, and the like. As shown above, device safety can be increased even if the transmission mode control itself does not have to rely on precise current activity decisions.

The controller not only identifies a particular activity, but also permeates, even if the actuation in the permeation mode does not depend on any predefined actuation profile corresponding to some identified mode of motion. The continuous force adjustment operation present in the mode is combined with the predefined operation profile required at a particular stage of the detected activity to provide continuous force adjustment assistance and a predefined operation profile when desired. Can be adapted to switch between.

In a preferred embodiment, the minimum assist is selected so that the residual force remains less than 30 N in the limb, preferably less than 20 N in the limb, especially less than 10 N in the limb. obtain. However, usually the residual force is still greater than 0.5N, especially greater than 1N, especially between 0.5N and 5N for at least a portion of the exercise, particularly 50% of the periodic exercise, preferably. Is at least 66% of the periodic movement, particularly preferably at least 3/4 of the periodic movement.

Other mechanisms may be used, but in the most preferred embodiment, at least one force transfer element is a tendon such as a cable or rope whose extension is wound or unwound using an electric motor such as a step motor or brushless motor. Is. The motor can be a brushless motor in particular, and the brushless motor is particularly preferred because it can be easily controlled and provide sufficiently high torque to the assisted limb when assistance is needed. In a preferred embodiment, the force transfer element is guided within the sagging sheath. That is, the force transfer element does not have to be a Bowden cable or similar, which simplifies the overall construction of the wearable active auxiliary device.

Basically, the control device provides the user with slack in the force transfer element of 10 cm or less, preferably 7 cm or less, particularly preferably 5 cm or less, during the transition from the selected minimum aid to a higher assist. It is noted that it is adapted to model elongation so that it needs to be overcome by being rolled up before it provides perceptible assistance.

Since the model depends on the "average user" for modeling, the resiliency factor uniformly causes the model's error, which is usually associated with small errors, even if there is some slack in the system. do. Therefore, in a preferred embodiment, a particular size with multiple parameters does not need to be entered into the system.

In a preferred embodiment, it may be useful to guide the force transfer element so that it extends beyond one or more joints. In this way, forces can be applied over many parts of the (periodic) movement. If the controller is adapted to model the elongation of at least one force transmitting element to be stretched, it is highly preferred to take into account friction as well as the actual size currently required.

In a preferred embodiment, it is taken into account that the variable active assist device must be equipped with a plurality of clothing-like elements and the like that the user needs to wear (to ensure that active assist is provided). Compared to regular garments, such garment-like elements are still significantly harder and also have a higher weight than conventional garments. When moving with such wearable auxiliary devices, the additional friction caused by clothing-like elements etc. needs to be overcome and often provides zero force to the limbs when accelerating parts of the human body. That alone is not enough. Rather, in certain cases, it is preferred that the user is completely unaffected by wearing an auxiliary suit. Thus, in true transmission mode with zero assist, it is also desired to prevent "negative" assist, whereby effects such as friction and inertia do not affect the user. Therefore, these effects should be compensated.

In a preferred embodiment of a wearable active assist device, there may be antagonistic passive elements that help stabilize joints and the like, even when the torque being assisted is actively applied in only one direction. In this case, in transmission mode, the antagonistic passive element also needs to be countered. In such cases, any limb assistance arises not only from residual stabilization of the joint, but also from active empowering exercise, which still provides some assistance.

It is noted that any model implemented or used by the controller may be designed to take into account the organizational compliance and / or body shape of the user wearing the active auxiliary device as part of the model. That is, preferably the user himself is considered an integral part of the controller of the system being worn. It allows the controller to assist the user in a manner that utilizes the human body's compliance as if it were a spring-damper system that stores and / or attenuates energy from force transfer elements. And thereby avoiding instability in the control scheme, thereby helping to stabilize any potential instability during the control action and simultaneously allowing a sudden increase in assistance when required. Ensure safe operation. Thus, an additional level of safety may be achieved that allows the system to assist with a high level of assistance in a sudden but controlled manner, if required.

At least one force transmission element that can be expanded or contracted in response to the movement or posture currently detected by multiple sensors, even if non-assisted limb assistance is provided by the wearable active assist device of the invention. It may be useful to model the extension of the motor and output the motor actuation signal according to the current modeled extension of at least one force transmitting element that can be expanded and contracted, and taking into account the selected limb assist degree. It is considered to be inventive in itself. That is, the transmission mode can be used as a reference, especially during active assistance with less than the maximum possible assistance, and any actual assistance may provide the degree of limb assistance that is actually assisted. Can be combined by further stretching and contracting at least one force transmitting element. From this it can be understood that the transmission mode can be combined with other auxiliary modes that allow continuous assistance over any given movement of at least one selected minimum level of assistance.

When referring to actuators, it should be noted that not only electric motors are available. For example, in the context of the present invention, such motors can also be hydraulic or barometric. Even techniques that resemble artificial muscles and allow control of artificial muscles can be used. It will be appreciated that devices can utilize, for example, electrical strain, magnetostriction and the like.

Protection is also sought for the control device of the wearable active auxiliary device having the motor and control device, the motor being operable to provide limb assistance, via at least one force transfer element stretched and contracted by the motor. Coupled to an actively assisted limb, the controller outputs an input for signals from multiple sensors, a signal processing stage for processing the signals, and a motor activation signal according to the processed sensor signals. It has an output stage for the control device, the model stage is equipped with a model stage for the user's current movement and / or posture detected by the sensor, and the compliance and movement of the human body tissue. Adapted to model the elongation of at least one force transfer element in a manner that maintains sub-threshold assist perceptible by the user, taking into account both the inertia and / or friction of the opposing wearable active auxiliary device. The output stage is adapted to output a motor actuation signal according to the current modeled extension and required limb assistance.

In this control, the same schematic idea of the invention is applied to take into account the inertia and / or friction of the components so that they can be compensated for instead without even adjusting the level of support to a minimum. By including it, the effects of wearable auxiliary devices that are barely noticed by the user can be obtained. From this, even if minimum assistance is not required, transmission mode helps in increasing precision and a given amount of assistance can be reached, which is baseline from minimum (= transmission) mode. It will be clear that it can be carried out by using as. As can be understood, this is done by taking into account at least one of the friction and / or inertial components, even if minimal assistance is not required, and by providing the disclosed concept. Can also be implemented.

The present invention is described herein with reference to the drawings.

FIG. 1 shows a schematic view of a wearable active auxiliary device according to the present invention.

FIG. 2 shows details of a wearable active auxiliary device showing a spring as a restorative elastic element and a cuff. The restorative elastic element is provided in series with a force transmitting element that can be expanded and contracted, and a cuff arrangement is provided on the limb. Placed around, but with constraints to constrain spring elongation to maximum possible elongation.

FIG. 3 shows a description of the model used by the control device of the wearable active auxiliary device according to the present invention.

FIG. 4 shows a schematic high-level block diagram for modeling the transparent behavior of a wearable active auxiliary device according to the present invention.

FIG. 5a shows a more detailed model component, namely the compliance compensation component.

FIG. 5b shows a more detailed model component, namely the speed compensation component.

FIG. 5c shows a more detailed model component, namely Stability Element Force Compensation.

FIG. 5d shows a more detailed model component, i.e., a position compensation component.

FIG. 6a shows a force-tendon length relationship for various forces that are repeatedly strengthened in a periodic manner.

FIG. 6b shows in more detail the force-tendon length relationship for fixed forces and repeated force enhancements. Note that the encoder count of the rotary actuator is shown instead of the tendon length.

FIG. 6c shows the force-tendon length relationship of FIG. 6 along with the average behavior obtained after repeated periodic motions.

FIG. 6d is a proof that the force applied to the tendon can be precisely controlled.

FIG. 6e shows the force-tendon length relationship with respect to various postures.

FIG. 7 illustrates the different tendon lengths required for minimum support and / or transmission mode in different postures.

FIG. 8 shows the force acting on the knee moment arm during transmission mode when moving at low speed, and shows that only the minimum force is applied during transmission mode.

According to FIG. 1, the wearable active auxiliary device 1 comprises a motor 2 and a control device 6, which is operable and used to provide assistance to the limb 3 of the user 4 and is used by the motor. Coupled to the limb 3 via at least one stretchable force transfer element 5, the controller 6 has inputs for signals 7a, 7b, 7c, 7d from the plurality of sensors 8a, 8b, 8c, 8d. However, the controller has a signal processing stage for processing the input signals 7a-7d from the plurality of sensors 8a-8d, and an output stage 9 for outputting the motor operation signal 10 according to the processed sensor signals. However, the control device further has a limb assist degree selection input 11 for selecting the limb assist degree, and the signal processor stage of the control device 6 is set to the user's motion currently detected by using the sensors 8a-8d. Correspondingly, the elongation of at least one stretchable force transfer element 5 is modeled and according to the current model stretch of at least one stretchable force transfer element 5 and in response to the selected minimum limb assist. , Adapted to output the motor actuation signal 10.

It should be noted that in the embodiments shown, the degree of limb assistance can be selected and the transmission mode implemented by the present invention is used as the minimum degree of limb assistance, but this does not necessarily have to be the case. .. In order to reduce the workload on the components of wearable active auxiliary devices such as motors, batteries, tendons, etc. and increase the life of the device, generally to maintain auxiliary precision, especially intentionally below the maximum degree of assistance. It is possible to keep.

Moreover, even in such cases, the transmission mode described herein can be used to define the basic elongation initiation for which additional assistance is provided, and thus the transmission mode is considered useful. Can be. In this way, for example, the overall support during periodic movements can be more constant. In such cases, the wearable active auxiliary device may include, for example, a motor and a control device, the motor being operable to provide joint assistance, via at least one force transfer element stretched and contracted by the motor. Coupled to the joints to be actively assisted, the controller outputs motor activation signals according to the inputs from multiple sensors, the signal processing stage for processing the signals, and the processed sensor signals. The control unit comprises a model stage, the model stage is adapted to model the extension of at least one force transfer element, and the modeling is of the user detected by the sensor. It is an embodiment that keeps the assist below the threshold perceptible by the user, taking into account both the current motion and posture and the inertia and / or friction of the wearable active assistive device that opposes the motion, and the output stage is currently It is adapted to output a motor actuation signal according to the modeled extension and / or required limb assistance of.

Now, returning to FIG. 1 and the embodiments shown therein, the user 4 is a human patient who uses the wearable active assist device for at least some period of time when a particular degree of assistance is requested but active assist is not required. Is.

The force transmission element is a tendon that is coiled and unwound on a reel that is rotated by a motor 2 so as to expand and contract the force transmission element. This can be seen, among other things, in FIG. A precise method by which a wearable active auxiliary device is constructed and the force transfer element is guided along the body of human user 4 is not shown in FIG. 1, but a reference is made to WO2018 / 122106A1 in this regard. obtain. Perhaps there are non-limiting examples of wearable active auxiliary devices in which the present invention can be implemented.

Many details, such as construction from different layers, are also shown in the cited documents. These are not absolutely necessary, but are also useful in the present invention. Accordingly, a sensor that has a structure according to the material cited and that follows the document cited and a control device that closely corresponds to the document cited other than those described herein. The wearable muscle assisting device having is fully usable for the present invention, but the present invention is not limited to the wearable active assisting device constructed as WO2018 / 122106A1 and the basics of the present invention. It should be noted that the idea can also be used in wearable active auxiliary devices with different constructions.

In the embodiments shown, the assisted joints are the user's knee and hip joints, especially the right leg joint, and a first triaxial accelerometer 8d is provided to the shin and a second triaxial accelerometer. The sensor is provided on the thigh. Further, an angle sensor is provided to indicate the bending angle of the right hip (sensor 8a) and the right knee (sensor 8c). An additional angle sensor may be provided on the ankle (not shown in FIG. 1). Different angles for different postures are also shown in FIG.

The force transfer element 5 in the embodiment shown is a tendon made from a non-extensible material and moored to the shin via cuffs 12 (see FIG. 2). A relatively resilient spiral spring 13 is provided between the tendon 5 and the cuffs 12. The coil spring 13 is moored to the cuffs 12 at one end thereof and to the end portion 5a of the tendon 5 at the other end portion thereof. The rope 14 is parallel to the spiral spring 13 and is guided into the coil spring 13. The length of the rope 14 is such that the restorative element 13 slackens within the rope to its maximum permissible extension. Of course, such constraints can also be implemented with restorative elements other than coil springs, such as rubber bands.

As can be seen in FIG. 3, the length of the tendon along the leg of the user 3 depends on the posture of the user, especially the bending angles of the knees and hips. Further, if the motor is mounted on the user's torso at a relatively high position, the length of the tendon also depends on the posture of the torso itself. The change in length of the tendon 5 depends on the path along which the tendon is particularly close to the human body when implemented by a wearable active auxiliary device. For example, the length varies depending on whether the tendon is guided in front of the buttocks or behind the buttocks. This can, of course, be taken into account. This is a virtual tendon length, in particular, by defining a virtual butt and a virtual leg that depend only on the current bending angle represented by angles α, β, and γ in FIG. 3, as shown in FIG. Is done by calculating.

And it will be apparent to those skilled in the art that any wearable auxiliary device will also have some mass that needs to be moved if the user wishes to move the limb. For example, when moving the shin, the cuffs 12 need to move the spring 13 and the rope 14 together with a part of the tendon 5. There is also some friction due to some garment-like structures of the wearable active auxiliary device, as well as friction inside the garment, and other causes of friction as is generally understood.

Here, if the user is provided with 0 assist as the minimum aid but is not adversely affected by the wearable active auxiliary device 1, the compensation component depicted in FIG. 4 is taken into account, inertia, and other effects. And the friction between interferences is compensated. Otherwise, the user may simply need to apply additional force to overcome the additional friction and inertia of the wearable active auxiliary device. It will also be clear that the inertia to be overcome depends on the particular movement. For example, if the shin is moved, the compensated inertia depends on whether the shin is supported during the early part of the swing phase or during the middle part of the swing phase. Initially, high acceleration is required, and in the middle of the swing phase, the velocity remains essentially constant for a short period of time, so the inertial force does not need to be compensated. The frictional force may also depend on the current speed and the current bending angle. (For the purpose of explaining the effects of friction and inertia, reference is made to the movement pattern and movement phase such as stance or swing leg, but the determination is not essential. Rather, the determination of the speed of the shin etc. is sufficient. Is.

As shown in FIG. 4, a model stage that models a penetrating force, in a preferred embodiment, captures the current posture or position of various parts of the human body, namely the torso, thighs, and shins. Take into account, and also take into account the current speeds of the torso, thighs and shins. Friction and inertia of each component, such as the torso, thighs and shins, as well as the restorative elemental force component can also be taken into account.

The motor also contributes to friction and inertia, thereby further contributing to sensors such as IMUs (Inertial Measurement Units) for the torso, thigh and shin respectively, preferably taking into account motor encoder signals as well. It will be clear that it should be. Using these signals, the position compensating force, the velocity compensating force, the friction compensating force, and the inertia compensating force can be calculated from the position compensating component, the speed compensating component, the friction compensating component, and the inertial compensating component, respectively.

The addition of these force components determines the overall transmissive force used to give the user the impression that the wearable active auxiliary device is neither assisting nor interfering with movement.

As can be seen in more detail in FIGS. 5a, 5b and 5d, each IMU comprises a gyro sensor and an accelerometer (particularly a triaxial accelerometer), with the gyro sensor and accelerometer being the gyro thigh and accelerometer, respectively. It is designated as a thigh, a gyro shin, an acceleration shin, a gyro body, an acceleration body, a gyro thigh, an acceleration thigh, a gyro shin, and an acceleration shin. From these sensor signals, the current thigh angle and the current shin angle are calculated, and these angles are used both in determining the velocity compensating component and in deriving the knee and hip angles. Then, from these angles, the virtual tail angle and the virtual leg length are calculated based on a model that is not user-specific, resulting in the proposed length of the virtual tendon.

This decision is repeated many times to calculate the change in virtual cable length over time.

The change in virtual cable length over time was derived from the motor encoder signal to determine if the current velocity is the correct velocity required to fully compensate for the current motion. Can be compared to the current speed of the motor. If necessary, the current speed can be corrected.

Similarly, to determine posture compensation, the torso angle, thigh angle and shin angle are again used, from which the knee angle is determined here. The knee and torso angles are compared to their initial angles and the difference determines the change in length. The initial thigh angle is also taken into account. In this way it can be determined whether the current elongation is correct or should be increased or decreased to avoid pulling or sagging. The result of this decision determines the force component for the current position.

Ultimately, organizational compliance and the effect of compliance on tendon displacement when force is applied compensates for the pressurization of the human body tissue when tendon is exerting force on the human body. It is possible and preferable that it can be taken into consideration in such an embodiment.

In a preferred actuator, a counter that counts the rotation angle encoder signal from the actuator is used to determine the twist or distortion of the tendon and, for example, the current and / or voltage applied to the actuator to simultaneously apply to the tendon. It should be noted that it is possible to estimate the force to be applied. In this way, the force-tendon length relationship can be established, and then the effect of tissue pressurization and the like can be estimated. Such a relationship is that pulling the tendon causes a slight change in the path that the tendon is guided along the body, and that the woven pieces of the wearable active auxiliary device slide against each other or somewhere in their position. It can be determined repeatedly, taking into account things that can be changed (leading to slight changes in the force-tendon length relationship). Such variations in behavior can be inferred, for example, from FIG. 6b. It should be noted that reference is made to the encoder count in FIG. 6 for the purpose of precision. While the encoder count is closely related to the tendon length, due to the twist or elimination of the tendon, the full rotation of the working motor is almost completely wound up by the larger diameter of the tendon. It is understood that the result is smaller when the tendon is completely extended than when it results in a larger change in tendon length due to being. Nonetheless, schematic patterns are easily seen and it is easy to compensate for such effects in controllers, especially microprocessor-based controllers with specific software modules. It can be seen from FIG. 6c that it is possible to derive the average behavior to increase the force or decrease it at high speed as shown in the curves AB-BC-CA.

For example, as is clear from FIG. 6a, the various maximum forces applied result in various changes, and as is also apparent from FIG. 6a or FIG. 6b, increasing the applied force is possible. It will also be appreciated that the results will be different from the behavior observed when the force is reduced, and that the effects described will be different in different postures as compared to FIG. 6c. Thus, whether general behavior and / or general effects such as tissue pressurization can be modeled and / or, as an alternative, force is applied first after a significant change in posture. Alternatively, the behavior can be modeled with particular consideration of whether or not the force is applied repeatedly. In addition, and / or as an alternative, the behavior can be modeled taking into account the maximum force currently or previously applied in a given pose. Further and / or as an alternative, the behavior can be modeled taking into account the previous posture, in particular the posture immediately preceding the current posture (s). FIG. 6d shows a potential force profile for determining a user's hardness model. The results depicted in FIG. 6e further show the different lengths of system sagging that can be compensated for.

The model is average data collected for a wide range of users, taking into account that daily variations can occur and that these variations can be compensated for by establishing or estimating the current force-tendon length relationship. And / or may be based on data collected specifically for a single user, especially for the particular user on which the device is worn and for a particular current method. Thus, in a preferred embodiment, the model can be determined by correlating the applied force to the measurement of tendon movement, whereby the system compensates for the movement of the tendon (feeds out the cable) of the user. Note that any potential high pressure point can be taken into account. When pressurized, of course, the tissue absorbs some energy, and this can be modeled in a manner that treats the tissue as a spring-damper system, which is a spring-damper system that absorbs energy from a force transfer element. It should also be noted that this helps stabilize potential instability during control actions and also improves the response of the system with safe operation when sudden increases in assistance are required.

The controller is adapted to model the elongation of the force transfer element independently of the user's size and weight, for example to determine the elongation required for the transmission mode independent of the user's size. It should be noted that since the force-tendon length relationship can be easily determined as is clear from the above, an exemption for this can be made for the force-tendon length relationship.

Here it may be possible to model the exact behavior of a wearable active auxiliary device for a particular user with a particular size, for example the patient's leg first bulges after an accident and the bulge over time. The modeling can often require a large number of measurements that may need to be repeated over and over again frequently.

Therefore, by using the restorative elements as described with respect to FIG. 2 to use the schematic parameters, and by precisely expanding and contracting only the tendons, the spring 13 does not completely extend into the transmission mode. Is desired. The tendon 5 is shortened sufficiently so that the element 14 no longer sags, for example, only when the patient is tired and the actual assistance is needed. Since the distance that the tendon 5 needs to be delivered is extremely small during the transmission mode of the present invention, active assistance can be provided almost immediately and without causing impact or spasm to the supported limb.

Claims (35)

A wearable active auxiliary device, wherein the wearable active auxiliary device comprises an actuator and a control device, the actuator providing limb assistance during use, via at least one force transfer element that can be expanded and contracted by the actuator. The control device is coupled to an actively assisted limb, the control device comprises a signal processing stage for processing inputs from the plurality of sensors and input signals from the plurality of sensors, and said processing. It has an output stage for outputting a motor operation signal according to a sensor signal, and the control device further has a limb assist degree selection input for selecting a limb assist degree.
The signal processing stage continuously models the extension of the at least one force transmitting element to be expanded and contracted in response to the motion or posture currently detected by the plurality of sensors, and the at least one to be expanded and contracted. A wearable active assistive device that is adapted to continuously output actuator activation signals according to the modeled extension of the force transfer element and in response to the selected minimum limb assist. The wearable active auxiliary device of claim 1, wherein the system response is determined in a manner that takes into account the physical characteristics of the human body, in particular the specific physical characteristics of a particular user wearing said device. The wearable active auxiliary device of claim 1 or 2, wherein the control device is adapted to model the extension of a force transfer element regardless of the size and weight of the user. One of claims 1 to 3, wherein the plurality of sensors include a gyro sensor and / or an acceleration sensor and / or a magnetic sensor and / or a stretch sensor and / or a motion sensor and / or an angle sensor. Wearable active auxiliary device as described in section. The wearable active auxiliary device of claim 4, wherein the plurality of sensors comprises at least one gyro sensor and / or an acceleration sensor for each of the plurality of limbs or joints of each leg. The wearable active auxiliary device of claim 5, wherein the extension of the current force transmitting element of one leg is determined in response to sensor signals from both legs. The control device models the elongation of the force transfer element independently of any force or tension display signal indicating force and / or tension in the force transfer element, especially independent of the load cell sensor measurement signal. The wearable active auxiliary device according to any one of claims 1 to 6, which is adapted as described above. Claims 1 to claim that the control device is adapted to model the elongation of the at least one force transmitting element to be expanded and contracted in a manner that takes into account the friction and / or inertia of the force transmitting element. The wearable active auxiliary device according to any one of 7. The restorative elastic element between the limb and the actuator, in particular the spring, is provided in series with the force transmitting element to be expanded and contracted, and a restrictor is provided to constrain the extension of the spring to maximum possible extension. The wearable active auxiliary device according to any one of claims 1 to 8. The restorative elastic element is the maximum residual force allowed at the selected minimum limb assist, and the spring is only less than or equal to the maximum possible difference between the standardized model and the stretch correction for a given user. The wearable active auxiliary device of claim 9, which has a resilience factor such that it can be stretched. The at least one force transmitting element to be expanded and contracted comprises a force transmitting element, and a reel is provided so as to wind up or rewind the force transmitting element when expanded and contracted, and in particular, the actuator is also a step motor or a brushless motor. The wearable active auxiliary device according to any one of claims 1 to 10. The wearable active auxiliary device according to any one of claims 1 to 11, wherein the force transmission element is guided by a sagging sheath. The wearable active auxiliary device according to any one of claims 1 to 12, wherein the at least one force transmission element expanded and contracted by the actuator extends beyond a plurality of joints. The wearable active auxiliary device according to claim 13, wherein at the minimum degree of assistance, the control device is adapted to maintain the extension so that the residual force is not perceived by the user. The wearable active auxiliary device according to claim 14, wherein the residual force in the limb is less than 30 N. The wearable active auxiliary device according to claim 15, wherein the residual force is smaller than 20 N. The wearable active auxiliary device according to claim 16, wherein the residual force is less than 10 N. The wearable active auxiliary device according to any one of claims 14 to 17, wherein the residual force induced by the force transmitting element is greater than 0.5 N. The wearable active auxiliary device of claim 18, wherein the residual force induced by the force transfer element is greater than 1N. The wearable active auxiliary device of claim 18, wherein the residual force induced by the force transfer element is between 0.5N and 5N. The wearable active auxiliary device according to any one of claims 14 to 20, wherein the residual force induced by the force transmitting element relates to at least a part of motion. 21. The wearable active auxiliary device of claim 21, wherein the residual force induced by the force transfer element relates to at least 50% of periodic motion. 22. The wearable active auxiliary device of claim 22, wherein the residual force induced by the force transfer element relates to at least 66% of periodic motion. 23. The wearable active auxiliary device of claim 23, wherein the residual force induced by the force transfer element relates to at least 75% of periodic motion. The controller rolls up less than 10 cm of slack in the force transfer element before providing perceptible assistance to the user as the controller transitions from the selected minimum degree of assistance to a degree of assistance higher than the minimum degree. The wearable active auxiliary device according to any one of claims 1 to 24, which is adapted to model the elongation as required to be overcome. 25. The wearable active auxiliary device of claim 25, wherein the slack of 7 cm or less of the force transfer element needs to be overcome by winding up before providing the user with perceptible assistance. 25. The wearable active auxiliary device of claim 25, wherein the slack of 5 cm or less of the force transfer element needs to be overcome by winding up before providing the user with perceptible assistance. The active assist device is adapted to assist leg activity, wherein the plurality of sensors comprises at least one gyro sensor and an acceleration sensor for each of the plurality of limbs or joints of each leg. The wearable active auxiliary device according to any one of claim 27. 28. The wearable active auxiliary device of claim 28, wherein the current force transmitting element of one leg is determined in response to sensor signals from both legs. In response to the sensor signal, the model identifies the current intended motion from the sensor signal, determines the phase in the identified current motion, and follows the expected progression of the current motion. 13. Wearable active auxiliary device. The controller is adapted to identify the activity as the current motion, which determines the phase in the current activity as the stance phase or the swing phase and / or with respect to the ground of the foot. 30. The wearable active auxiliary device described in any one of them. A control device for a wearable active auxiliary device, particularly a control device for a wearable active auxiliary device according to any one of claims 1 to 31.
The wearable active assist device comprises an actuator that is operable to provide limb assist and is actively assisted via at least one force transfer element that is expanded and contracted by the motor. Attached to the limbs to be
The control device is
Inputs for signals from multiple sensors and
A signal processing stage for processing the signal and
It has an output stage for outputting a motor operation signal according to the processed sensor signal, the control device includes a model stage, and the model stage is a model stage.
The user's current motion and / or posture detected by the sensor,
The at least one in a manner that maintains sub-threshold assistance perceptible by the user, taking into account the inertia and / or friction of the wearable active assistive device against exercise and / or the tissue compliance of the human body. Adapted to model said elongation of one force transfer element,
The output stage is a control device adapted to output the motor actuation signal according to the current modeled extension and required limb assistance. Adapted to model stretch components in a continuous manner without reference to a predefined force / auxiliary profile.
32. The controller of claim 32, in particular, adapted to model the stretch required in the minimal auxiliary transmission mode. The controller is further adapted to determine additional extension components that are simultaneously imparted in response to detected and / or identified movements, the additional extension being simultaneously conferred on the transmission mode extension. 33. The controller of claim 33. 34. The controller of claim 34, wherein the detected and / or identified exercise is a walking exercise, a stair climbing exercise, or a sitting transition exercise.

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